IY THE SHETLANDS 247 
yellow colour of the buccal cavity which is thereby 
revealed, and the display of which supplies, in my 
opinion—as in the other cases I have brought forward 
—the true motive of the bird’s conduct in this respect. 
Handsome—or, at any rate, outré—as the puffin’s 
beak is, it is hardly, if at all, more striking to the eye 
than is this vivid gleam of one bright colour, revealed 
suddenly in a flash-light by this distension of the 
mandibles. It is like the sword gleaming out of 
the scabbard, whose brightness comes as a surprise, 
whereas the latter, however rich and ornate, is a per- 
manent quantity, and so lacks the charm of novelty. 
The fact that the puffin’s beak is a superlative orna- 
ment does not, in my opinion, render it unlikely that 
there should be another one lying within it. It is 
absurd in such a matter to say that this or that is 
enough, and in the puffin’s case we are certainly 
debarred from doing so, since not only has the beak 
been decorated, but the parts adjacent to it, as well as 
the whole head, have also been, so as to join in the 
general effect. The eye is almost as salient a feature 
as the beak itself, and moreover, where the mandibles 
meet at their base, there is on either side a little 
orange button or rosette, formed by foldings of the 
naked skin, which must certainly rank as a sexual 
adornment in the eyes of all who believe in such 
a thing, and with which, apparently—as in the other 
cases—the inner coloration is continuous. 
The puffin, therefore, makes the seventh species of 
sea-bird in which, as I believe from my own observa- 
